Search

Oral cancer is one of the highest-incidence malignancies worldwide, with the occurrence of oral squamous cell carcinoma (OSCC) being the most frequently diagnosed form. A barrier for oral cancer management may arise from tumor cells that possess properties of cancer stemness, which has been recognized as a crucial factor in tumor recurrence and metastasis. As such, understanding the molecular mechanisms underlying these tumor cells may provide insights for improving cancer treatment. MRE11 is the core protein of the RAD50/MRE11/NBS1 complex with a primary role in DNA damage repair, and it has been diversely associated with tumor development including OSCC. In this study, we aimed to investigate the engagement of CD44, a cancer stemness marker functioning in the control of cell growth and motility, in OSCC malignancy under the influence of MRE11. We found that overexpression of MRE11 enhanced CD44 expression and tumorsphere formation in OSCC cells, whereas knockdown of MRE11 reduced these phenomena. In addition, the MRE11-promoted tumorsphere formation or cell migration ability was compromised in OSCC cells carrying siRNA that targets CD44, as was the MRE11-promoted AKT phosphorylation. These were further supported by analyzing clinical samples, where higher CD44 expression was associated with lymph node metastasis. Additionally, a positive correlation between the expression of MRE11 and CD44, or that of CD44 and phosphorylated AKT, was observed in OSCC tumor tissues. Finally, the expression of CD44 was found to be higher in the metastatic lung nodules from mice receiving tail vein-injection with MRE11-overexpressing OSCC cells compared with control mice, and a positive correlation between CD44 and phosphorylated AKT was also observed in these metastatic lung nodules. Altogether, our current study revealed a previously unidentified mechanism linking CD44 and AKT in MRE11-promoted OSCC malignancy, which may shed light to the development of novel therapeutic strategies in consideration of this new pathway in OSCC.

Objectives FOXA2 gene methylation links to the progression of cancers, but has not been documented in oral cancer. Herein, we explore the role of FOXA2 in the migration of oral cancer cells. Material and methods Methylation-specific PCR was applied for gene methylation. Wound healing and transwell experiments were tested for cell migration. FOXA2 expression in oral cancer tissues was addressed by immunohistochemistry, followed by statistical analysis of its association with clinical manifestations and patient survival. Results FOXA2 bound to the promoter of CDH1 and enhanced the expression of its gene product E-cadherin, and decreased the cancer cell migration activity. High FOXA2 expression in oral cancer tissues was associated with high E-cadherin expression, decreased lymph node metastasis, and increased patient survival. Conclusion FOXA2-E-cadherin link is involved in regulation of oral cancer cell metastasis and provides a new insight for the tumor suppressor activity of FOXA2 in oral cancer.

Background: Melatonin, produced by the pineal gland, is known for its antioxidant, oncostatic, and anti-inflammatory properties. However, studies on serum melatonin levels in different cancer types have yielded conflicting results, and little is known about the clinical significance of serum melatonin in oral squamous cell carcinoma (OSCC) in the Southern Asian population. Therefore, we explored its role in OSCC in this study. Methods: A total of 67 male OSCC patients and 78 healthy controls were enrolled in this case–control study. The serum levels of melatonin were determined by enzyme-linked immunosorbent assay (ELISA) and compared between the two groups. Results: The serum melatonin levels were significantly lower in OSCC patients compared with healthy controls (mean ± standard deviation, 15.0 ± 4.6 vs. 18.5 ± 11.8 pg/mL, p = 0.02). In the subgroup of age less than 55 years (mean age of OSCC), OSCC patients had a significantly decreased melatonin level than healthy controls (mean melatonin, 15.7 ± 12.6 vs. 20.8 ± 3.9 pg/mL, p = 0.02). Decreased serum melatonin (odds ratio (OR): 0.95, 95%CI: 0.91–0.99), alcohol consumption (OR: 29.02, 95%CI: 11.68–72.16), betel quid chewing (OR:136.44, 95%CI: 39.17–475.27), and cigarette smoking (OR:29.48, 95%CI: 11.06–78.60) all increased the risk of OSCC under univariate analyses of logistic regression. Betel quid chewing (OR: 45.98, 95%CI: 10.34–204.49) and cigarette smoking (OR:6.94, 95%CI: 1.60–30.16) were the independent risk factors for OSCC in Taiwan. In addition, a negative correlation between age and melatonin level was observed in healthy controls (Pearson r = −0.24, p = 0.03). However, the negative correlation was lost in patients with OSCC. Melatonin concentration had no association with the severity of OSCC. Conclusion: Overall, our study provides evidence that serum melatonin levels decreased in OSCC patients in Taiwan and the decreased level is much significant in young populations and suggests that the decreased melatonin was associated with OSCC, especially in young populations. Further studies are warranted to investigate whether melatonin can be a useful non-invasive screening tool for OSCC.

Oral cancer is the fourth most common type of cancer among males in Taiwan, and the prognosis for patients with advanced-stage oral squamous cell carcinoma (OSCC) remains poor. The present study investigated the prognostic value of three DNA repair genes, namely excision repair cross-complementing group 1 (ERCC1), ERCC2 and X-ray repair cross-complementing group 1 (XRCC1) in OSCC. The protein expression levels of XRCC1, ERCC1 and ERCC2 in oral cell lines were analyzed via western blotting and immunohistochemistry using samples from 98 patients with biopsy-proven OSCC, while the χ2 test was used to analyze the clinicopathological association. Kaplan-Meier estimates were used to determine the prognostic value of XRCC1, ERCC1 and ERCC2 for overall survival, and the log-rank test was used to evaluate the significance of differences. Multivariate analysis revealed a positive association between ERCC2 expression and OSCC recurrence (19.64-fold; 95% CI, 5.00-77.1; P

Background/purpose Oral metastatic carcinomas are rarely found in oral soft tissues. This study reported the clinicopathological features of 13 intraoral soft tissue metastatic carcinomas. Materials and methods A total of 13 intraoral soft tissue metastatic carcinomas were included in this study. The clinicopathological features of the 13 cases including the primary cancer site, metastatic intraoral soft tissue region, clinical presentation, and histopathological diagnoses were examined and reported. Results The 13 intraoral soft tissue metastatic carcinomas occurred in 13 patients (11 males and 2 females) with a mean age of 59.4 (range, 39–78) years. Nine cases originated from the liver (69.2%), and one each from the colon (7.7%), pancreas (7.7%), thyroid (7.7%), and kidney (7.7%). The histopathological diagnoses of the metastatic lesions were hepatocellular carcinoma in 9 cases, adenocarcinomas in 2 cases (one each from the colon and pancreas), clear cell carcinoma of the kidney in one case, and follicular thyroid carcinoma in one case. The gingiva and alveolar mucosa were the major metastatic sites (10 cases, 76.9%), followed by the buccal mucosa (two cases, 15.4%), and soft palate (one case, 7.7%). Twelve metastatic lesions manifested as ulcerated, easy-bleeding, and pyogenic granuloma-like lesions. Conclusion The results of our series of 13 cases indicate that intraoral soft tissue metastatic carcinomas have a male predilection with a male to female ratio of 11:2, are commonly found in the gingiva and alveolar mucosa (76.9%), present frequently as an easy-bleeding pyogenic granuloma-like lesion (92.3%). In addition, the most common primary cancer site is the liver.

The spinel LiZn x Mn 2− x O 4 ( x ≤0.10) cathode materials have been synthesized by solution combustion method at 600 °C for 3 h. The structure and the morphology of LiZn x Mn 2− x O 4 were characterized by X-ray diffraction (XRD) analysis and scanning electron microscopy (SEM), respectively. All the obtained samples were identified as the spinel structure of LiMn 2 O 4 , the lattice parameters of samples decreased and the particle size increased as the Zn content increased. The effects of Zn-doping on the electrochemical characteristics of LiMn 2 O 4 were investigated by galvanostatic charge–discharge experiments, cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Among them, LiZn 0.05 Mn 1.95 O 4 particles presented outstanding cycling stability with a capacity retention of 82.9% at a discharge rate of 1 C (1 C=148 mA h g −1 ) after 500 cycles. Spinel LiZn 0.05 Mn 1.95 O 4 had reversible cycling performance, revealing that doping LiMn 2 O 4 with Zn improves its electrochemical performance.

LiMn2O4was synthesized by flameless solution combustion at 600°C for 3 hours (h). The influence of HNO3on the morphologies, crystal structure and electrochemical performances of the material was investigated. The results show that the main phase of all synthesized products is LiMn2O4, and the impurities are Mn2O3or Mn3O4depending on the concentration of HNO3(CHNO3). While CHNO3=0 and 15 mol L-1, the impurity was Mn2O3, when the concentrations of HNO3from 3 to 9 mol L-1, the impurity was Mn3O4; at CHNO3=12 mol L-1, the synthesized product was single phase; CHNO3≤12 mol L-1, with the increase of CHNO3, particles size grew from 70-130 nm to 140-500 nm, however, CHNO3is up to 15 mol L-1, particles become small (70-140 nm); the single phase of LiMn2O4obtained the maximum first discharge capacity (119.7 mAh g-1) at CHNO3=12 mol L-1, but its retention rate was undesirable, while CHNO3=15 mol L-1, the cycling performance of the product was the optimum with first discharge capacity of 118.5 mAh g-1and capacity retention of 90.9 % after 40 cycles at 0.2 C.

A series of LiMg x Mn 2-x O 4 (x ≤ 0.20) cathode materials were rapidly synthesized at a low temperature of 500 °C for 1 h by a solid-state combustion process. The morphologies and crystal structures of LiMg x Mn 2-x O 4 were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD), respectively. All LiMg x Mn 2-x O 4 samples exhibited a single phase LiMn 2 O 4 spinel structure with good crystallinity. The linear decrease of the lattice parameters with the increase of Mg-doping content could suggest that Mg 2+ ions had put into the spinel LiMn 2 O 4 lattice substituting for Mn 3+ . The effect of Mg 2+ ions on the electrochemical performance of LiMg x Mn 2-x O 4 was investigated by galvanostatic charge-discharge test, cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The results showed that the Mg-doped LiMn 2 O 4 possessed better cycling stability, for example, a capacity retention of 93.2% for LiMg 0.08 Mn 1.92 O 4 after 150 cycles at 0.2C.

Spinel LiMn 2 O 4 cathode material was rapidly prepared by solid-state combustion synthesis based on a two-stage calcination progress which used lithium carbonate and manganese carbonate as raw materials and citric acid as a fuel. The structure and physicochemical properties of the obtained LiMn 2 O 4 powders were investigated by thermogravimetric analysis (TG) and differential thermal analysis (DSC), X-ray diffraction (XRD), scanning electron microscopy (SEM), galvanostatic charge–discharge test, cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The results show that the successful formation of single-phase LiMn 2 O 4 product is highly dependent on its second-stage calcination temperature. Compared with other conditions, the as-prepared LiMn 2 O 4 powders which experienced the second-stage, and calcined at 700 °C is the most uniform, and the charge transfer resistance ( R ct ) is the lowest, accompanying the best electrochemical activity and highest discharge capacity. Its initial discharge specific capacity is 119.1 mA h/g.

An alternative electrodeposition technology, which provides an efficient way to complete a better interface contact between electroactive materials and metal foil substrates, was used to prepare Ni3S2/Ni composites in aqueous solutions contained thiourea (TU). The deposition parameters, such as time and TU concentration, were optimized. Surface morphology, chemical composition, and crystal structure of Ni3S2/Ni composites were analyzed using scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), and X-ray diffraction (XRD), respectively. A Ni3S2/Ni composite, which consisted of submicrometer grains with size in the range of 0.2–2 μm, was obtained. Galavostatic battery testing shows that the submicrometer Ni3S2/Ni4 composites as cathodes for lithium batteries exhibit a high specific capacity of 338 mAh g–1 at a current density of 0.17 A/g (∼0.6 C), extraordinary capacity retention as well as 95.3% after 100 cycles, and outstanding rate performance, for example, still delivering 180...

The LiMg0.06Mn1.94O4calcined at 500 °C for 3 hours then sintered at 600 °C, 700 °C and 800 °C for 3 hours by flameless liquid-phase combustion synthesis are prepared. Particle properties were characterized by X-ray diffraction, scanning electron microscopy and Fourier transform infrared spectroscopy. Besides, galvanostatic tests and electrochemical impedance spectroscopy were performed to investigate the cycling performance. Particle properties analyses showed that LiMg0.06Mn1.94O4sintered at 600 °C has a single phase and the average grain size is about 80-200 nm with a little agglomeration, it also displays the highest initial capacity of 114.2 mAh/g and still remains 82.7% after 40 cycles. Results showed that sintered temperature by nitric acid assisted liquid-phase combustion method should be 600 °C.

This paper presents a method to identify the noise radiation regions of an acoustic source from a small number of measurement points. First, the acoustic radiation modes that contribute to the acoustic far-field are selected. Next, the velocities on the surface of the acoustic source are reconstructed based on the selected acoustic radiation modes. Finally, the noise radiation regions are determined from the surface areas that have larger amplitude of the reconstructed velocities. Numerical simulations of a rectangular plate are conducted to validate the efficiency of the proposed approach, and different analyzing frequencies are considered. The proposed approach facilitates the identification of the noise radiation regions of an acoustic source and can also be applied to reduce the radiation noise in the far-field.

LiMn2O4 cathode materials were successfully prepared by solid-state combustion synthesis with the lithium carbonate and the manganese carbonate as raw materials and the citric acid as fuel. The effect of citric acid on composition, microstructure and electrochemical properties of LiMn2O4 cathode materials was investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), cyclic voltammetry (CV) and galvanostatic charge-discharge test. The results indicated that a pure phase of LiMn2O4 was prepared at the product with 5 wt% citric acid. However, an impure phase of Mn3O4 was found at other products. The crystal size distribution was more uniform at the higher content of citric acid. The products with 5 wt% and 10 wt% citric acid, the cubic structure morphologies of which were more prominent, and the capacities of which were higher than that of bare LiMn2O4 product. Their initial discharge specific capacities were 119.6 mAh•g-1 and 114.0 mAh•g-1, and their capacity retention ratios after 40 cycles were 85.0% and 87.7%, respectively.

The spinel Mg-doped LiMn2-xMgxO4（0≤x≤0.10）lithium ion cathode material was prepared by LiNO3, Mn(Ac)2.4H2O and Mg(Ac)2.4H2O by a low-temperature flameless solution combustion at 400°C, and HNO3 was used as oxidant. The results showed that the crystallinity of prepared material was superior to the pure LiMn2O4, and this method was better than traditional solid-state method. The particle sizes of the Mg-doped spinel LiMn2-xMgxO4 decreased with the increase of Mg doping, and the particle sizes were 50 to 90 nm; the crystal lattice interface was clear. The original capacities of Mg-doped were lower than that of undoped LiMn2O4 (109.2 mAh/g) excepts for x(Mg)=0.04, original capacity of which was 128mAh/g. However, the rentions of all the doped spinels were higher than that of undoped spinel.

A modified chloride bath being suitable for high speed electrodeposition was used to deposit smooth and flexible Fe foils. Their surface morphology and crystal structures were observed using scanning electron microscopy (SEM) and X-ray diffraction (XRD), respectively. The results showed that the morphology and crystal structures of Fe foils changed drastically in the presence of Mn 2+ , Sm 3+ , La 3+ and Fe 3+ cations. Several morphology shapes were prepared in this paper. This will allow for further studying the effect of surface morphology on catalytic, magnetic and corrosive properties.

Electrodeposition processes of Ni, Fe and Ni–Fe alloys on 316 stainless steel surfaces in fluorborate baths were studied using conventional electrochemical techniques and atomic force microscopy. The results showed that these processes occurred under mass transfer control, associated with nucleation and growth process. Cathodic current–time transients indicated that the nucleation and growth of Ni–Fe alloy was different from that of the single metal (Ni or Fe). For one, two nucleation and growth processes occurred during Ni–Fe alloy codeposition. Also, there was a nucleation and growth process of Ni–Fe alloy on Ni–Fe clusters, due to a change of the Ni–Fe alloy composition and phase. Homogeneous Ni–Fe alloy deposits could be obtained by pulse potential plating. AFM images of Ni, Fe and Ni–Fe deposits prepared by pulse potential plating revealed the following results: (1) the growth rate of Ni nuclei was faster in parallel than in perpendicular to the 316 electrode surface; (2) for Fe nuclei, the preferential growth direction was perpendicular to the 316 electrode surface; and (3) for Ni–Fe nuclei, there was no preferential growth direction and uniformly hemispherical Ni–Fe clusters were obtained.

A fluorborate bath being suitable for the continuous electrodeposition system was used to deposit Ni1−xFex (0.1

A new base-type polyaniline piezoelectric bacteria culture (B-PAn-P) system for rapid detection of bacteria population was proposed. In this system, interdigital electrode coated with a base-type polyaniline/poly vinyl alcohol (B-PAn/PVA) composite film was used as probe (B-PAn probe) in place of steel electrode in multi-channel series piezoelectric quartz crystal (MSPQC) system. The probe was directly connected to the piezoelectric detection system. B-PAn/PVA film can react with CO2 produced by the growth of bacteria in culture medium, which caused the film electrical properties change. This change can be sensitively monitored by piezoelectric detection system. The superiority of using proposed probe instead of steel electrode were: firstly, it was more sensitive to bacteria growth response and secondly, it did not require a specially formulated culture medium which was demanded in MSPQC system. Just like MSPQC, proposed system can be used to detect bacteria population. When used to quantitatively determine Pseudomonas aeruginosa, the frequency detection time (FDT) obtained in frequency shift curve had a linear relationship with the logarithm values of initial concentration of P. aeruginosa in the range of 10 to 106 cfu ml−1. The detection limit was 10 cfu ml−1. Compared with MSPQC system, proposed system was more sensitive and no special demand to culture medium.

The reaction of N,N'-di(2-pyridyl)formamidine (HDpyF) with MnCl 2 ·4H 2 O afforded the complex MnCl 2 (HDpyF), which was characterized by X-ray crystallography. The HDpyF ligand chelates to the Mn(II) center through the first and the third nitrogen atoms to form a six-membered ring, leaving the second and the fourth nitrogen atoms uncoordinated. The HDpyF ligand is crystallographically disordered such that two different molecules can be solved. The neutral HDpyF ligand adopts the new s-cis-syn-s-trans conformation.

The compound N, N′-di(6-methyl-2-pyridyl)formamidine (HDMepyF) has been exploited in preparation of porous materials of divalent metal complexes of the formulae M(HDMepyF)2(NO3)2 (M=Cd, 1; Co, 2; Ni, 3) and M(HDMepyF)2X2 (M=Mn, X=Cl, 4; M=Mn, X=Br, 5; M=Ni, X=Cl, 6; M=Ni, X=Br, 7). Their structures have been determined by X-ray crystallography. Each metal center of these complexes is approximately octahedrally coordinated by four nitrogen and two halogen or oxygen donor atoms. Complexes 1– 5 and 7 self-assemble through similar hydrogen bonding motifs which involve the C–H⋅sX (X=Cl, Br or O) hydrogen bondings and π–π stacking interactions between the HDMepyF ligand and the X atoms to form porous structures.

The 2-aminopyridine ligand has been exploited in preparation of divalent metal complexes of the formulae [H(2-ampy)][MnCl3(H2O)] 1 and [H(2-ampy)]2[Mn2Cl6(2-ampy)2] 2, where 2-ampy is 2-aminopyridine. Their crystal structures have been determined by X-ray crystallography. Both complexes self-assemble through similar hydrogen bonding motifs which involve three N–H⋯Cl interactions between the 2-aminopyridinium cation and the chloride atoms. Each repeating unit of complexes 1 and 2, [MnCl3(H2O)]− and [Mn2Cl6(2-ampy)]2−, respectively, is doubly edge-sharing to form one-dimensional chains which are cross-linked by hydrogen bonding to the [H(2-ampy)]+ cations. In complex 2, two different 2-aminopyridine molecules were observed. One bridges the Mn atoms directly, while the other, through hydrogen bonding interaction, bridges Mn atoms via the chloride atoms. The structural role of the 2-aminopyridinium cation on the aggregation of the metal ions is discussed.

Reaction of [PdCl2(CH3CN)2] with HDpyF (HDpyF = bis(2-pyridyl)formamidine) in CH3CN afforded a yellow product [Pd2Cl2(DpyF)2] which was characterized by X-ray crystallography. The DpyF− ligand coordinates to the Pd atoms in a new tridentate fashion, forming a chelating and a bridging bonding modes. The molecules are chiral due to the ligand constraints. Spontaneous resolution of the racemic product can be achieved by crystallization of the yellow product in CH3CN/ether, and a CD spectrum can be obtained.

From a solution prepared by a reaction of Mo2(O2CCH3)4 with KTp* (Tp*=hydridotris(3,5-dimethylpyrazolyl)borate, HB(Me2Pz)3), in diglyme at room temperature followed by addition of excess (CH3)3SiBr to the red solution in refluxing THF, the complexes [HB(Me2Pz)3)BH][Br3Mo(μ-Br)3MoTp*] (1), [Mo4(μ3-O)2(μ2-O)2(μ2-OH)2(O)4(Me2PzH)6](Br)4(Me2PzH2)2 (2) and MoBr2Tp*(Me2PzH) (3), were obtained. Their structures have been determined by X-ray crystallography. The anion of complex 1 consists of two octahedra sharing a common triangular face so those three Br atoms bridge the Mo atoms. The metal centers are also chelated by a tridentate Tp* ligand and coordinated by three Br atoms. Structural comparison of 1 and [HB(Me2Pz)3)BH][Br3Mo(μ-Br)2(μ-H)MoTp*] shows that replacement of the bridging hydride atom by the bromide atom led to the lengthening of the Mo–Mo bond distance by about 0.36 A. In complex 2, the four octahedra are bridged together through edges. The two molybdenum atoms in the asymmetric unit have different environments although both are formally seven-coordinated. The average oxidation state of molybdenum is +5, and the four electrons available for Mo–Mo bonding form two localized Mo–Mo single bonds. Complex 2 can be classified into the structural type Mo4XaYbZc, in which a+b+c=16. The formation of the cation, [HB(Me2Pz)3)BH]+, 2 and 3 shows the ready cleavage of the B–N bond of the Tp* ligand.

For level-of-service analysis, the 1994 Highway Capacity Manual divides freeways into basic sections, ramps and ramp junctions, and weaving areas. Different criteria are applied to these components to define levels of service. This use of nonuniform criteria makes it difficult to assess operating consistency in terms of the spatial change of traffic operations throughout a freeway system. This problem can be alleviated by using vehicle speed to establish a set of uniform criteria for the systemwide evaluation of freeway design and operation. Toward this end, the relationships between speed and other related geometric design and traffic parameters should be established. The spatial variations of flow characteristics on freeways, and the need to account for such variations in capacity and level-of-service analysis, are discussed first by analyzing observed speed-flow relationships. This is followed by a discussion on the selection and application of uniform criteria for planning and design.

In the crystal structure of the title molecule, C13H14N4, the two pyridyl rings are not coplanar but twisted about the C—N bond with an interplanar angle of 71.1 (1)°. In the crystal, the molecules form dimers, situated on crystallographic centres of inversion, which are connected via a pair of N—H...N hydrogen bonds. C—H...π-electron ring interactions are also present in the crystal structure. The title molecule adopts an s–cis–anti–s–cis conformation in the solid state.

In the crystal structure of the title compound, C(11)H(10)N(4), the dihedral angle between the two pyridyl rings is 36.1 (1)°. The mol-ecules are connected via two strong N-H⋯N and two weak C-H⋯N hydrogen bonds into dimers, which are located on centers of inversion. This compound adopts the s-trans-anti-s-cis conformation in the solid state.